1 Now concerning things offered to idols: We know that we all have knowledge. Knowledge puffs up, but love edifies.
2 And if anyone thinks that he knows anything, he knows nothing yet as he ought to know.
3 But if anyone loves God, this one is known by Him.
Probably the fact that the church contained both converted Jews and Gentiles was the source of controversy. The distinction between the clean and the unclean animals had been for centuries an in superable barrier to fellowship between Jew and Gentile. Wherever the devout Jew lived he required a special butcher to prepare his meat, one who was trained to decide whether the meat was killed according to the law or not. The Jew would under no circumstances eat meat which had not been certified as free from legal blemish and officially prepared according to the law. The custom today still prevails in the eating of specially prepared “kosher” meat. But the Gentiles had been accustomed to obtain their meat anywhere, as long as it was good to eat, and they made no distinction between clean and unclean animals. Much of this meat which was sold in these pagan temples consisted of remnants of sacrifices brought to the heathen altars and placed on sale after the priests had used their own portion for ceremonial purposes and their own private use. It was meat of the very highest quality, for nothing but the best was accepted by the priests in sacrifices to their heathen gods. Moreover, it was usually cheap, for it was donated for sacrifice, and therefore it was a boon to poor Christians who might not otherwise enjoy this highest quality meat.
The legalists said, however, that it was wrong to eat such meat because it had been offered unto idols and served in an ungodly heathen temple; while those who took a more liberal view contended that there was nothing wrong with it because they were under grace. — DeHaan, pages 93-94.
knowledge (v.1) — In this case, knowledge that idols are not deities and, therefore, that there is no intrinsic harm in eating meat offered to them.
puffs up (v.1) = lit. “blows up, inflates” — self-conceit, pride
edifies (v.1) = builds up — Knowledge puffs up, love builds up.
If anyone thinks that he knows anything, he knows nothing yet as he ought to know (v.2) — In the original the tenses vary, in the first place the perfect tense, rendered “knows,” signifies knowledge acquired; in the next two the past definite or aorist tense signifies the beginning of the process of acquiring knowledge. We may therefore suggest the following rendering: “if a man imagines he has fully acquired true knowledge, he has not even begun to know how it ought to be gained.” — Vine, page 57.
The point of verse 3 is that love, not knowledge is the key to doing God’s will.